Rotating knife tenderometer



Aug. 9, 1966 K. BouscHART ETAL 3,264,866

ROTATING KNIFE TENDEROMETER Original Filed Feb. 7. 1962 6 Sheets-*Sheet l FIG.

JNVENToRs KENNETH BouscHAR-r EARL A, MEYER AT TORN EYB Aug' 9, 1966 K. BouscHART ETAL 3,264,866

ROTATING KNIFE TENDEROMETER Original Filed Feb. '7, 1962 6 Sheets-Sheet 2 INVENTORS K E N N ETH BOUSCHART EARL A. MEYER ATTORNEYS Aug- 9 1966 K. BoUscHART ETAL 3,264,866

ROTATING KNIFE TENDEROMETER original Filed Feb. v. 1962 e sheets-sheer. a

INVENTOR KENNErH BoUscHA EARL A. MEYER ATTORN EYS Aug 9, 1965 K. BoUscHAR-r ETAL 3,264,866

ROTATING KNIFE TENDEROMETER Original Filed Feb. 7, 1962 6 Sheets-Sheet 4 FBG. 7

1N VEN TRS KENNETH BOUSCHART EARL A. MEYER ATTORNEYb Aug- 9, 1966 K. BouscHARr ETAL 3,264,866

ROTATING KNIFE TENDEROMETER Original Filed Feb. '7. 1962 6 Sheets-Sheet 5 ATTORNEYS Aug 9, 1966 K. BouscHART I-:TAL 3,264,866

ROTATING KNIFE TENDEROMETER Original Filed Feb. 7, 1962 QZ WDOI EmPmEOEmOZmC.

COUNTER KENNETH BOUSCHA RT EARL. A. Y

MEYER L, QZ/wa' SWITCH I3I POSITION United States Patent O 3,264,866 RU'EA'IING KNIFE TENDERUMETER Kenneth Bouschart and Earl A. Meyer, Madison, Wis.,

assignors to Feed Service Corporation, Crete, Nebr., a

corporation of Nebraska Continuation of application Ser. No. 171,713, Feb. 7,

1962. This application lian. 7, 1964, Ser. No. 339,058

` 12 Claims. (Cl. 73-78) This invention relates to a method and apparatus for the measurement of the tenderness of a material and, more particularly, to such for the tenderness testing of meat after slaughter.

This application is a continuation of our co-pending application, Serial No. 171,713, filed February 7, 1962, now abandoned.

Contemporary meat tenderness testing methods and apparatus all have certain characteristics or features which limit the usefulness thereof. Some provide a single value of tenderness over a very small region of the meat whereby, due to the non-homogeneous character of meat, a large number of tests are required to obtain a representative result. Others .require that the meat specimen be removed from the carcass for testing. Furthermore, none of the prior art arrangements appears to be capable of determining the tenderness of meat with accuracy.

The tenderness of meat is essentially a subjective evaluation by the person chewing the meat when cooked and in most instances is not truly evaluated independently of such characteristics as avor, texture, and perhaps juiciness. The degree to which a particular physical or chemical test agrees with an organoleptic test (i.e. a chew test) determines the usefulness of such testing procedure. It is common knowledge, however, that it is not always necessary for an individual to actually chew a cooked meat sample in order to form a subjective opinion of its tenderness; he frequently prejudges the tenderness of the meat as he cuts it. If the meat cuts easily with a dull knife, such as a table knife, he expects from his previous experience that it will be tender to chew. If it is very difficult to cut with a dull knife, he ex-pects it to be correspondingly tough to chew. It has now been discovered, (l) that differences in meat tenderness can be detected by a suitably instrumented dull knife device and, (2) that there is a reasonable correlation between `a tenderness rating by such a device and an organoleptic test. The method and apparatus of this invention involves the use of a dull knife or cutter. A dull knife with the sharpness of an ordinary table knife is required since a sharp knife, such as a steak knife, minimizes the difference between tough and tender meat, cutting them both easily.

An object of this invention is the provision of a method and apparatus for the testing of meat tenderness in which a plurality of successive passes of a dull knife along a predetermined path on the meat are made, the average ldepth of meat cut per pass of the knife under substantially constant knife-to-meat force being taken as an indication of the tenderness of the meat.

Another object of the invention is the provision of a method of testing the tenderness of meat which method includes making a plurality of successive cuts with a dull knife along a predetermined path on the meat while maintaining a substantially constant force between the knife and meat determining by physical means the number of the cuts and the total depth of penetration of the dull knife or cutter in the meat, the average depth of meat and sensibly indicating the tenderness of said meat cut being taken as indicative of the tenderness of the meat.

A further object of the invention is the provision of a meat tenderness tester comprising a dull blade, means making a plurality of successive passes of the blade along a predetermined path on the meat while maintaining a substantially constant force between the blade and meat, and means measuring the depth of meat cut during successive passes.

A still further object of the invention is the provision of a cutter for a meat testing device having a blade which has a dull portion adjacent the tip thereof and a sharp portion adjacent the dull portion for cutting tough sinews.

An additional object of the invention is the provision of a meat tenderness testing apparatus in which a circular cut is made in the meat whereby local variations in tenderness which exist when cutting with and against the meat grain are averaged out in the tenderness measurement.

These and other objects and advantages will become apparent from the following detailed description when taken with the accompanying drawings. It will be runderstood that the drawings are for purposes of illustration and do not define the scope or limits of the invention, reference being had for the latter purpose to the appended claims.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1A is an axial sectional view of one end portion of a testing, device embodying the invention, With parts broken away and parts shown in elevation.

FIGURE 1B is a similar view of the other end portion of the device of FIGURE 1A.

FIGURE 2 is a fragmentary transverse sectional view on the line II-II of FIGURE 1B, in the direction of the arrows.

FIGURE 3 is a fragmentary transverse sectional view on the line III-III of FIGURE 1B, in the direction of the arrows.

FIGURE 4 is a transverse sectional view on the line IV-IV of FIGURE 1B, in the direction of the arrows.

FIGURE 5 is a fragmentary transverse sectional view on the line V-V of FIGURE 1A, in the direction of the arrows.

FIGURE 6 is a fragmentary transverse sectional View on the line VI-VI of FIGURE 1B, in the direction of the arrows.

. FIGURE 7 is a transverse sectional view on the line VII-VII of FIGURE 1B, in the direction of the arrows.

FIGURE 8 is a fragmentary transverse sectional view of the testing device, including the recording stylus or pen, on the line VIII-VIII of FIGURE 1A, in the direction of the arrows.

FIGURE 9 is a fragmentary transverse sectional view on the line IX-IX of FIGURE 1A, in the direction of the arrows.

FIGURE 10 is a side elevational view, with parts in axial section, of the cutter of the device of FIGURES 1A and 1B.

FIGURE 10A shows the cutter edge portion developed or flattened.

FIGURE ll is a fragmentary axial sectional view, to a larger scale, on the lines XI-XI of FIGURES 1A and 1B in the direction of the arrows, land with parts in elevation.

FIGURE 11A is a transverse sectional view on the line 11a-11a of FIGURE 11, in the direction of the arrows.

FIGURE 12 is a wiring diagram.

FIGURE 13 is a chart showing the action of the carnoperated counter switch of FIGURE 12.

FIGURES 14 and 15 are views of the home and stop cams, respectively.

FIGURE 16 is a fragmentary view of the stepping relay ratchet wheel and pawl assembly.

FIGURE 17 is a chart showing the action of the home and stop cams.

Reference is first made to FIGURES 1 to l1, inclusive, wherein there is shown a portable or lield model of a meat tenderness testing device embodying this invention. The portable model employs a rotary cutter, or knife, 21 mounted within a hollow cylindrical housing 22 to which hand grips 23 and 24 are secured. When not in use, the front end may be closed `by a screw cap 25 threaded thereto, which cap is removed before use.

The front and rear ends of the housing 22 are closed by covers 26 nd 27, respectively, iixedly secured thereto as by screw fastening means. A desirably synchronous gear-head motor 28 lis mounted on a motor mounting wall 29 for rotatably driving the cutter 21. Said wall 29 is secured over the open end of a cup-shaped part or header 31 and spaced from the circular wall 32 thereof by a plurality of hollow cylindrical members 33. Said members 33 are held in place by securing means such as screws threaded thereto. The assembled parts 29, 31 and 33 are secured within the housing 22 by suitable means such as screws.

The motor shaft 34 is coupled through reducing gears 35, 36, 37 and 38 to drive means 39. Said drive means includes a coupling portion 40 and a generally hollow cylindrical portion 41 provided with longitudinal slots 42 intermediate the ends thereof. The dr-ive means 39 is secured to a drive member or shaft 43 of cylindrical shape, as by means of a transverse pin 44. The member 43 is provided with rollers 45 turnable on a shaft 46 which passes therethrough and which is held in place by suitable means, such as a tight fit. The rollers 45 are turnable so that their shaft 46 is freely slidable along the slots 42 which receive the rollers. The free or front end of the member 43 rotatably supports a ball 48 carried in a socket 49 secured to the adjacent end of a spring-mounted force-transmitting rod 51.

Ball bearings 52 for axial movement are carried within a shaft support and driven member 53, said member 53 being rotatably mounted with respect to an intermediate support wall 54 by means of ball bearings 55. The wall 54 is held in place with respect to the housing 22, as by means of screws or the like. Thus it will be understood that the drive tube 41 is axially movable relative to the drive member 43, but is relatively rotatably fixed with respect thereto by means of the slot 42 and roller 45 connection. A drive connection to the cutter 21 is thus effected from the motor 28 thru the motor coupling 40, drive shaft 43, roller-carrying shaft 46, rollers 45 and drive tube 41, which is iixedly secured within the cutter extension or hub portion 56 thereof. The motor mounting wall 29 provides rear-end support for the drive assembly, further support being provided by the walls 54 and 69.

A constant force along the cutter axis in a forward or left-hand direction, as seen in FIGURES lA and 1B, is provided by means of four springs 57 comprising bands of stainless steel or the like rolled into coils on spools 58. The spools 58 are rotatably carried in bifurcated arms 59 xed to the support wall 54, as by suitable fastening means such as screws 61. From these spools 58 the bands extend rearwardly and are xed to a pressure plate 62 by suitable clamping means, such as the plates 60. These coiled bands exert a substantially constant force against unwinding and tend to rewind with approximately the same constant force. Thus the pressure plate 62 is urged forward with a constant force supplied thereto by said coiled bands and transmits that force to the drive tube 41 thru ball bearing 63 and a cup-shaped head 64 mounted on the rear end of said drive tube and retaining the ball bearing. The head 64 may be adjustably held in place on the drive tube 41 by having a hub portion press fitted thereinto. Collar member 66 containing a set screw 65 is thereby adjustably mounted on the drive tube 41 in order to limit the stroke thereof to a distance less than the travel of the wiper arm of transducer 158. This protects the transducer which desirably has only a two-inch travel.

A hollow cylindrical member or housing 68 is disposed between the front cover 26 and a forward wall 69. The wall 69 acts as a support for the ball bearing 71 which, in turn, supports the ball bearing device 72 which allows for axial movement of the drive tube 41 and the cutter 21 carried thereby. The cover 26 is provided with a plurality of, desirably six, sharply-pointed members or spikes 73 which are adapted to engage the meat sample under test, thereby preventing rotation thereof-with the rotating cutter 21 and also stabilizing the instrument. The cap 25 is threaded to the front of the device and protects the pointed members 73 and the cutter 21 when the device is not in use.

Within the cutter 21 is a meat follower 74 in the form of a hollow cylinder with a closing wall at one end forming, in effect, a cup-shaped device. The purpose of the follower is to support the wall of the meat being cut so it does not fall into the groove and be recut. The meat follower is slightly smaller in diameter than the cutter 21 so as to slide therewithin. It is resiliently biased axially toward the left, as viewed in FIGURE 1A, by means of a coil compression spring 75 encircling the rod 51 and acting between the socket 49 and the inner end of a connecting screw 76.

The screw 76 passes through, and serves to connect, the transverse wall of the follower 74 to a tubular member 77 into which it is threaded. A boss on said transverse wall strengthens it at this point without adding unnecessary weight. The screw also draws the outer end of said member 77 into engagement with the tboss 80 around the receiving aperture in said wall. The hub portion 56 of the cutter 21 limits the movement of shoulder 78 which thereby prevents the follower from extending beyond the cutting edge, at the same time allowing the spring 75 to cause said follower to move with the 'cutter 21 as it advances into the meat being tested. The rearward portion of the tubular member 77, beyond the shoulder 78, serves as a housing for the spring 75.

The recording mechanism for the device includes a drum 79 and a recording pen assembly 81. The pen assembly is fixedly mounted on a door 82, pivotally secured to the housing 22 as by means of a hinge 83, (FIGURE 5). A recording pen 84 is resiliently biased by a spring (not shown) into a chart when mounted on the drum 79 when the door 82 is closed. The drum 79, with the chart thereon, moves axially with and is rotated with the cutter 21 during a meat-testing operation, by virtue of the connection between the drum 79 and the drive tube 41, as by means of a screw 85, while the pen remains fixed with respect to the housing to make a trace on the chart.

The drum 79 is formed with a slit 86 which extends longitudinally and through which the ends of the chart may be inserted and gripped by the paper-winding rollers 87 and 88. The roller 87 is carried by a shaft 89 rotatively mounted with respect to the drum 79 and provided with a knob 91. The knob 91 is fixed to one end of the shaft 89 for manual rotation thereon and turnable counterclockwise, as viewed in FIGURE 8, to draw the chart ends between the rollers and the chart tightly on the drum.

When the device is used in a vertical position, that is, with its longitudinal axis vertical and the cutter 21 facing down, it will be apparent that the weight of the reciprocable mechanism, if not compensated for, would add to the force provided by the springs 57 and different indications would be obtained than when operating in a horizontal position. In order to -compensate for the weight of the reciprocating mechanism during use in such vertical position, we include two constant-force springs 92 of the same type as the springs 57.

Said springs 92 are mounted on spools 93 rotatably supported in bifurcated members 94 secured to the wall 32 of the cupshaped header 31. The free ends of the springs are secured to the outstanding flange 95 of a hollow 'cylindrical member 96. The hub portion of the member 96 may be locked or unlocked with respect to the pressure plate 62, as to `a hub portion 97 thereof, by means of a set screw 93. When the screw 98 is tightened on the hub portion 97, the springs 92 exert a constant upward force, or one to the right as Viewed in FIGURE 1B, on the reciprocable mechanism to exactly compensate for the weight thereof, whereby the total downward force of the cutter on the meat comprises only that exerted by the springs 57, as in the case of operation in .a horizontal position, but where the screw 98 is loosened.

Electrically, there are three distinct operations: wnd, run and home The wind operation provides for one revolution and auotmatic stop to aid in inserting the recording paper; the run operation provides for a predetermined number of revolutions and automatic stop for meat testing; and the home operation provides for abandoning a test before completion and quickly advancing to the home or initial position.

To explain the electrical operation, the three operations in the order listed are: wind, run and home Push switch 102 is labeled wind or home. It is the wind switch before and after a test, but it is the home switch during a test.

Referring now to the wi-ring diagram of FIGURE 12, the instrument is readied for operation by connecting the male line plug 99 to a source of 115 volt-60 cycle power and turning on the toggle switch 100 to a circuit protected by fuse 90 or other suitable protective device. Pilot lamp 101 should glow as an indication that the circuit is energized. The wind operation is initiated by momentarily depressing the Wind or home push switch 102. This supplies 115 volt power from lead 110 and pin 103 of motor connector device 104 through switch 102 and pin 105 through lead 106 to a coil terminal of relay 107, pulling down on relay armature 108. This removes the movable contacts 109, 111, 112 and 113 from stationary contacts 114, 115, 116 and 117, respectively, and brings them into engagement with stationary contacts 118, 119, 121 and 122, respectively, on relay 107.

A 115 volt circuit then exists from lead 120, movable contact 123 to fixed contact 124 of stepping relay 125, then on through line 126 through fixed contact 119 to movable contact 111, then through lead 127, pin 128 and lead 129 to the motor 28, causing it to start. Also as a branch from lead 129, there is a circuit through counter switch 131 when in the up position illustrated, lead 132 back through pin 183 and lead 184 through relay contacts 109 to contact 118 and on to the same terminal of the coil of relay 107, holding that relay in even after the wind or home switch 102 is released.

The motor 28 -continues to drive in series the reduction gears 35-36, 37-38, the first pair stepping down the speed 24 to 1, as from the motor armature speed of 3600 r.p.m. to a cam shaft speed of 150 r.p.m. and the second pair further stepping down the speed to 1, as to another cam shaft speed of r.p.m., at which speed the drum 79 is adapted to run. The gear train is Icontained in one assembly with the motor, FIGURE 2, and the cam 133 which operates the counter switch 131 (FIGURE 3). A chart showing the action of the cam-operated counter switch 131 is shown in FIGURE 13. Zero degrees (0) on the chart represents the point at which the motor is started. When point A on the cam 133 of the counter switch 131 is reached, the counter switch movable contact leaves its upper fixed contact and engages its lower fixed contact. Since the counter switch movable contact was supplying the upper fixed contact with 115 volt power to hold in relay 107, the relay now returns to the normal de-energized position. That is, movable contacts 109, 111, 112 and 113 will leave stationary contacts 118, 119, 121 and 122 and return to stationary contacts 114, 115, 116 and 117, respectively.

Relay 107 returning to the normal position would cause the motor to stop running except that the counter switch 131 is now made to engage its lower fixed contact which has volt power on it. This comes about from the input 115 volt power going along lead 120 to stepping relay movable contact 123, to fixed Contact 124, then to fixed contact 116, t-o movable contact 112, lback to stepping relay fixed contact 134, movable contact 135, along lead 136 to pin 137 and then to lower fixed contact of counter switch 131.

Therefore, the motor continues to run until point B on the cam 133 of counter switch 131 is reached, at which time the movable contact of the counter switch 131 leaves its lower fixed contact and returns to its upper fixed contact. Since the relay 107 is then no longer energized, the motor 23 no longer has a source of 115 volt power and, therefore, stops running. This additional running interval between A and B is necessary in order for the motor 28 and, therefore, the recording drum 79, to `st-op in the same location that it does after a run operation, thereby enabling easy insertion and removal of the recording tape. This wind operation may be repeated any number of times without affecting the next run operation.

The run operation is initiated by momentarily operating the run switch 130. This supplies 115 volt power from lead 110 and pin 103 through pin 139 and lead 141 to stepping relay fixed contact 142 to movable contact 143, to the A.C. to D.C. power supply 144 which applies D.C. to the coil terminals of the stepping relay 125. The desirably .03 microfarad capacitor 159 and the desirably 510 ohm resistor 160 shunting the stepping relay coil terminals are for transient suppression. The stepping relay armature operates as will now be described.

The stepping relay is composed of a cam shaft containing nonmetallic cams 145 and 146, FIGURES 14 and 15, and a metallic ratchet wheel 14S, FIGURE 16, containing thirty-six teeth, an electromagnet (see the coil of this in FIGURE l2) and pawl assembly 149, only fragmentarily shown, which operates the ratchet wheel, and the electrical contacts. The electrical contacts are of two types, those which are operated by the cams and those which are operated by the armature of the electromagnet. The electrical position of the single-pole, double-throw cam operated contacts is determined by the cut of the cam. They can vbe in either one of the two switch positions for any one of the thirty-six cam positions determined by the ratchet wheel. The relay in question has three such singlepole, double-throw cam operated switches each being operated by its own specially cut cam. The first two have been named home and stop to correspond with the function they perform While the third is a spare for eventual use with the integrating circuit.

The electromagnet operated contacts are similar to those on an ordinary relay in that they operate every time the electromagnet operates. These contacts are also singlepole, double-throw and have been named interrupter contacts. They are shown in FIGURE 12 in the deenergized position. The actual stepping or advancing operation is shown in FIGURE 16. Further information maybe obtained from page 2 of a brochure titled Rotary Stepping Switches, published by Automatic Electric, Inc., of Northlake, Illinois. The first three sketches on said page show what happens when the electromagnet is energized. The spring-loaded pawl of the assembly 149 is pulled to the right, engaging the next tooth on the ratchet wheel 148 and storing potential energy in the spring, not shown. Upon de-energizing the electr-omagnet, the spring pushes the pawl to the left, rotating the ratchet Wheel ten degrees (10:1/6 revolution) Iin the clockwise direction as shown in the last three sketches, the second thereof being reproduced as FIGURE 16. The contacts are shown in the home position in FIGURE 12. This is the position in which they remain except during a test. The table of FIGURE 17 shows the position of each cam-operated switch for each of the thirty-six cam positions. X on the table indicates the switch position opposite that shown 7 in FIGURE 12. The switch position indication in the table can be seen to correspond to the cams shown in FIG- URES 14 and 15.

Upon releasing the run switch 138 the stepping relay armature 151 returns to its original position at the same time advancing the ratchet and cams 10. FIGURE 17 shows that the cam-operated contacts 143 and 123 of stepping relay 125 change position when advancing from home H to 2. In other words, movable contacts 143 and 123 leave stationary contacts 142 and 124, and move to stationary contacts 154 and 155, respectively. When this occurs, a 115 volt power circuit is established from the 115 volt supply through lead 120 to stepping relay movable contact 123, to fixed contact 155, then to relay fixed contact 115, movable contact 111, then through lead 127 to pin 128 and on through lead 129 to the motor 28 causing it to start running. The 115 volt power is also on the movable contact of counter switch 131. The other motor connection is made through pin 130 of male plug 104 back to the line plug 99.

Since counter switch 131 engages its upper fixed contact 1 and since the lead 132 from there through pin 183 and lead 184 ends through movable contact 109 at a no connection at fixed contact 114 of relay 107, nothing else operates at this instant. As the cutter 21 and, therefore, the cam 133 which operates the counter switch 131 near the end of the first revolution, point A, as indicated on counter switch position chart, FIGURE 13 is reached at which time counter switch movable contact leaves its upper fixed contact 1 and engages its lower fixed contact 3.

Since there is a 115 volt power on the movable contact of counter switch 131, the same will be connected to the lower fixed contact thereof, and from there through pin 137, lead 136, to stepping relay fixed contact 154 to movable contact 143, then to the A.C. to D.C. power supply 144 and then to the coil terminals of the stepping relay 125. This again operates the armature of said relay. When the cam 133 allows the movable contact of the counter switch 131 to leave its lower fixed contact and return t-o its upper fixed contact, 115 volt power is removed from the stepping relay coil terminals and the stepping relay 125 advances 10 to position 3 of FIGURE 17.

When the cutter 21 has neared the end of each revolution, the counter switch 131 operates as before and causes the stepping relay 125 to advance one position. One the sixteenth revolution (position 17 in FIGURE 17) both the counter switch 131 and the stepping relay armature 151 operate as in previous revolutions. But when the counter switch 131 returns, its movable contact returning to upper fixed Contact, the stepping relay 125 advances to chart position 18 at which time the movable contact 123 leaves stationary contact 155 and returns to stationary contact 124.

Since the stepping relay movable contact 123, which always has 115 volt power on it, has left stationary contact 155, this breaks the 115 volt power circuit through relay fixed contact 115 and movable contact 111, through lead 127 and pin 128, stopping the motor 28. At the same time, stepping relay movable contact 123 engages iixed contact 124, w-hich completes 115 volt power circuit through relay fixed contact 116 to movable contact 112, and then to the stepping relay 125 fixed interrupter contact 134, to movable contact 135, to stepping relay 125 Xed contact 154 to movable contact 143, to the A.C. to D.C. power supply 144 to again operate the armature 151 of the stepping relay 125. To this point everything seems to be the same as in previous revolutions.

However, when the stepping relay armature 151 operates, the interrupter movable Contact 135 leaves the stationary contact 134 and engages the unconnected sta tionary contact 157. This removes the 115 volt power from the A.C. to D.C. power supply 144, thereby allowing the stepping relay armature 151 to return to the deenergized position and advancing the cams another 10 to the next home position, without making another revolution of the cutter 21 in position 18. Since this stepping relay has 36 positions and it is desired to have 16 operating plus 1 home position per run cycle, there is room for two run cycles per complete revolution of the stepping relay 125. This leaves 1 extra position per run cycle or two extra positions per complete revolution of the stepping relay 125. This is the reason for rapidly passing over position 18.

The number of predetermined revolutions can be changed from one to seventeen by changing the stop cam 146 to allow the stop movable contact 123 to return to the stationary contact 124 after the desired number of revolutions, thereby repidly advancing over the unused positions. The run cycle could also be extended up to 35 revolutions by providing only one run cycle per stepping relay revolution. It is helpful to -notice that only stepping relay 125 operates during a run operation and that only relay 107 operates during a wind operation.

The home operation, used to abandon a test prior to completion, is initiated by depressing and holding the wind or home switch 102. To follow the circuits, it must be remembered that the stepping relay 125 movable contacts 143 and 123 are engaged with stationary contacts 154 and 155, respectively, since this is during a run operation. When the wind or home switch 102 is depressed, volt power is applied through pin 105 and lead 106 to the relay 107 coil terminals.

This operates relay 107, causing movable contacts 109, 111, 112 and 113 to lleave stationary contacts 114, 115, 116 and 117, and engage stationary contacts 118, 119, 121 and 122, respectively. This completes a circuit from the 115 volt power supply to relay 107fixed contact 121 to movable contact 112, then to stepping relay 125 interrupter contact 134, to contact 135, then to stepping relay 125 contact 154 to contact 143, then to the A.C. to D.C. power supply 144 which operates said stepping relay.

However, operation of the stepping relay 125 causes the interrupter movable contact to leave the stationary contact 134 which removes the 115 volt power from the A.C. to D.C. power supply 144, thereby causing the stepping relay 125 to return to the de-energized position and advancing the cams 10. This, however, causes the interrupter movable contact 135 to return to the stationary contact 134 which again completes the circuit to operate the stepping relay 125. This making and breaking of the circuit to the stepping relay coil causes the rachet and cam assembly to rapidly advance to the home position, at which point the home movable contact 143 leaves the stationary contact 154 and returns to the stationary contact 142. This stops the rapid advance as indicated by the stopping of the clicking sound. This is the indication of when it is time to release the wind or home switch 102.

It will be noted that when the stepping relay 125 has returned to home position, the circuit is ready to go into a wind operation. Since the wind or home switch 102 is not released until after the stepping relay has stopped in the home position, the device will be in a wind operation for up to one revolution of the cutter 21, depending upon when the revolution of said cutter, the lhome position of the said stepping relay is reached.

From the foregoing it will be seen that we have devised an instrument particularly adapted for testing the tenderness of meat and wherein a chart is produced on a piece of paper wound on a drum which rotates with the tenderometer knife and on which a trace is made by a stylus which may be a ball-point pen 84 held stationary with respect to an enclosing housing. The indication of tenderness may be obtained by first removing the chart from the drum and laying it fiat. The area bounded by the traces drawn on the second and last revolutions, and bounded on the sides by lines essentially perpendicular to the traces with loci at the starting and end points of each trace, represents the relative tenderness of the meat.

The second rather than the first trace is used to avoid anomalies which sometime result as the cutter seats in on the first trace. The greater the area, the more tender the meat. The area can be measured 'by any convenient method, including mechanical methods such as with a planimeter.

It will also be understood that, although we have referred to meat, yet we do not wish to be limited to use of the instrument solely on meat as it is just as Well adapted for testing the ease with which other products may be cut or penetrated, such products including plastics and gelatins. In standardizing the instrument, it is intended to first calibrate it with a specific reproducible material such as foamed polystyrene, 4otherwise known as Styrofoam- Although not essential to the invention, a potentiometer 158, secured to the housing and having a wiper contact movable axially with the cutter, may he provided to actuate an electrical instrument in correspondence with the penetration of the cutter yinto the meat.

The rotary cutting action described herein is not mandatory but is convenient and desirable. Strai-ght line cutting in the same direction or even reciprocating cutting are examples of other types of cutting action which might also be used. Regardless of the cutting motion employed, the indication of tenderness is the average depth of meat cut per knife passage under constant conditions. 'Ilhe rotary motion tends to average out location variations in tenderness which exis-t when cutting with and again-st the meat grain.

It will be understood that the parts of the instrument not shown in FIGURES 1 to l1, inclusive, may be housed in a suitable control box (not shown). Thus, the 4control box may have all the parts of the wiring diagram enclosed in the dashed area on the right in FIGURE l2.

The shape of cutter 21, cutting edge down, is illustrated in FIGURE 10A where the cutter is slit and opened up on a plane surface. The direction of travel is to the right, as shown by the arrow, with the relatively dull cutting edge portion shown at 152. Proceeding to the left from the lowermost portion of the blade, the edge rises sharply to provide a relief in the region 153. The sharp rise here allows the cutter to respond rapidly in faithfully tracing the tenderness profile when irregularities, such as sinews, are passed over, -thereby giving a true point by point indication. The region 156 serves a dual function as a pilot in advance of the relatively dull cutter portion 152 as well as a relief in addition to 153 to insure that the cutting edge 152 is the only portion of cutter 21 in contact with the bottom f the cut. Since regions 153 and 156 do n-o cutting whatsoever, they are left completely dull.

The cutter 21 as originally developed had a very sharp portion called the sinew cutter in the 156 region, practically at the 152-156 boundary. A sinew, if uncut, could mask a very tender portion under the sinew. The purpose of the sinew cutter was therefore to cut the sinew after a few revolutions when further penetration into the meat would put the sharp sinew cutter in contact with the sinew. The function of this former sinew cutter is now performed by the presently somewhat less dull cutting edge 152 of the cutter 21. This eliminates the Very sharp sinew cutter which would not be conducive to long term reproducibility because of rapid dulling.

In the operation of the device, the cutter 21 is rotated at a low speed of, say l revolutions per minute by the motor 28. Since the cutter and chart drum 79 are mounted on the same shaft, they obviously rotate together at the same speed. As the blade of the knife penetrates into the meat upon rotation thereof, the drum chart moves downwardly relative to the pen and a trace is made on the chart. In the unrolled condition o-f the chart, there appears, a single trace for each revolution of the knife. It will be apparent that adjacent traces will be spaced further apart when the meat is tender and closer together where the meat is tough.

A numerical index of tenderness can readily be obtained by measuring the area between the second and last trace of each set. The larger the area, the more tender the region tested. The area thus measured will represent a value corresponding to the average point by point tenderness obtained on the particular test. In comparing the tenderness of one meat sample with another on a uniform scale, it is necessary to adopt standard conditions. All factors, except the meat sample itself, should remain constant from test to test; this includes the number of revolutions, blade configuration, blade dullness, and the normal force exerted by the rotating blade on the meat.

In using the instrument, the control box power cord plug 99 is connected to a source of 115 volt, 60 cycle power. A cable, shown schematically in FIGURE 12, is used to connect the control box to the male plug 104 mounted on the desirably transparent plastic housing 22 of the instrument. The protective cover 25 is removed rfrom the cutter end of the instrument.

A mode of operation is selected, that is, vertical or horizontal, by either engaging or disengaging the counterbalance plate 95. For vertical operation, the cutter 21 is depressed to the fully retracted position and the counterbalance set screw 98 is tightened on the pressure plate hub 97 as illustrated in FIGURE 1B. For horizontal operation, set screw 98 is left loose. The power is applied by operating the toggle switch 100 on the control box. The adjacent pilot light 101 should glow, indicating that the instrument is ready to operate.

The chart-paper door 82 maynow be opened. One end of a desirably 9 inch long piece of 2% inch paper tape is placed in the recording drum slot and the winding knob 91 on top of the drum 79 turned just enough to grip the paper. The wind or home button 102 may now be momentarily pressed to cause the drum to rotate one revolution. When it stops, the free end of the paper is inserted in the same slot and the wind knob turned until said paper is drawn up tightly. The chart-paper door 82 should now be closed and latched, bringing the stylus or pen 84 into contact with the paper.

To perform a test, the instrument is placed firmly and squarely in contact with the exposed muscle region of a round of meat or any other sort of material, the tenderness or permeability of which is to be tested. For cornparative test purposes, if on meat, it is important that the test be performed in the same region each time. While exerting a Iforce of two pounds or more, the run switch 13S, which may be on the forward handle 23, is pressed. This starts the revolution sequence. At the end of the elected number of revolutions the instrument will stop.

The instrument is then withdrawn and the chart-paper door opened. The chart paper is removable upon unwinding the knob 91. To read the indicated tenderness, the total area between the second and last traces of the recorder pen is determined. The area can be measured with a planimeter.

If it is desired to abandon a test before completion, the instrument can be cycled to the starting position quickly by depressing the wind or home button 102 until the homing is completed as indicated by the stopping of the control box clicking. The instrument may continue run ning up to one more revolution at this time.

If the recording stylus of the assembly 81 is a pen containing ink which flows too slowly for effective operation at low temperatures such as those in meat coolers, it is desirable to heat it electrically. This may be accomplished by incororating in the pen a resistor 161 energized from the secondary winding of a transformer 162 through a control rheostat 163. The primary winding of the transformer may receive power by connection across leads 164 and 165, as illustrated in FIGURE l2.

Instead of having the pins 105, 183, 137, 128, 139, 103 and 130 directly engaging corresponding sockets on the control box for respective connection with the leads 106, 184, 136, 127, 141, 110 and the grounded lead from the desirably grounding type plug 99, we desirably employ a detachable cable diagrammatically represented at 166. Thus, such a cable includes leads 167 to 173, inclusive. The left hand end of each of these leads, as viewed in FIGURE l2, terminates in a socket for respectively receiving the pins 105, 183, 137, 128, 139, 103 and 130. The right hand end of each of the same -leads terminates in a pin adapted to be received in sockets respectively terminating the left hand ends of the leads 106, 184, 136, 127, 141, 110 and the grounded lead from plug 99, also as viewed in FIGURE l2.

Having now described our invention in detail in accordance with the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individua-l parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention as set forth in the following claims.

We claim:

1. Apparatus for determining the tenderness of a material comprising a dull cutter, means successively passing the cutter along a predetermined path on the material under test to cut the same, means maintaining a substantially constant force between the cutter and material during each cutting pass, and means for determining the average penetration -per cutting pass of said cutter into said material for a plurality of such passes.

2. Apparatus according to claim 1 including means continuously recording the penetration of the cutter relative to a predetermined reference point.

3. Apparatus according to claim 1 wherein the means successively passing the cutter along a predetermined path on the material includes a rotatable shaft upon which the cutter is mounted, and means rotating the shaft so that the cutter makes a circular cut in the material.

4. Apparatus according to claim 3, wherein the material is meat.

5. Apparatus according to claim 1 wherein said cutter has a blade with an edge, said edge having a relatively dull cutting portion dropping -sharply as a relief at the rear end of said cutting portion and preceded by a gently rising portion to function as an additional relief and a pilot for the cutting portion.

6. Apparatus according to 4clai-m 5, wherein the cutter is formed at the edge portion of a hollow cylinder, and the cutting edge is generally helically shaped.

7. A tenderness testing apparatus comprising a cutter having an edge, a rotatable shaft, means securing the cutter to the rotatable shaft with the edge displaced from the shaft axis, means rotating the shaft, a chart drum secured to the shaft and rotatable therewith, and a stylus adapted to engage a strip of paper when on the chart drum.

8. An instrument for determining tenderness comprising a hollow cylindrical housing, a hollow cylindrical cutter closed by a wall at its rear end and disposed in and mounted for axial movement with respect to said housing, a wall in and extending transversely of said housing, an electric motor disposed in said housing and carried by said wall, drive means for -said cutter extending from said motor, a connection between said motor and said drive means, said drive means including a hollow cylindrical portion, a drum carried by said hollow cylindrical portion, means to mount a strip of recording paper on said drum, a stylu-s carried by `said housing and adapted to make a graph on the paper as the drum turns and moves axially with said hollow cylindrical portion, a shaft connected to said drive means coaxial with and disposed in said hollow cylindrical portion, means for transmitting rotary motion, while allowing relative axial motion, between said shaft and hollow cylindrical portion, a hollow cylindrical follower disposed in and movable with respect to said cutter, a rod extending rearwardly from said follower through the rear wall of said cutter, and means resiliently biasing said follower outwardly with respect to said cutter, away from said shaft, and disposed inside of said hollow cylindrical portion, to allow said follower to trail the cutter in the axial direction as the material being tested is cut.

9. An instrument for determining tenderness comprising a hollow cylindrical housing, a hollow cylindrical cutter closed by a wall at its rear end and disposed in and mounted for axial movement with respect to said housing, a wall in and extending transversely of said hou-sing, an electric motor disposed in said housing and carried by said wall, drive means for said cutter extending from said motor, a connection between said motor and said drive means, said drive means including a hollow cylindrical portion, a drum carried by said hollow cylindrical portion, means to mount a strip of recording paper on said drum, a stylus carried by said housing and adapted to make a graph on the paper as the drum turns and moves axially with said hollow cylindrical portion, said hollow cylindrical portion being provided with longitudinally extending slots, a shaft connected to said drive means coaxial with and disposed in said hollow cylindrical portion and a pin extending transversely through said shaft, a drive roller on each end portion of said pin and each disposed in one of the slots in said hollow cylindrical portion for transmitting rotary motion, while allowing relative axial motion, between said shaft and hollow cylindrical portion, a hollow cylindrical follower disposed in and movable with respect to said cutter, a rod extending rearwardly from said follower through the rear wall of said cutter, and means resiliently biasing said follower outwardly with respect to said cutter, away from said shaft, and disposed inside of said hollow cylindrical portion.

10. An instrument for determining tenderness comprising a hollow cylindrical transparent housing, front and rear covers closing the ends of said housing, a hollow `cylindrical cutter closed by a wall at its rear end, disposed in, and mounted for axial movement with respect to said housing, hand grips projecting laterally from said housing, a screw cap threaded to the front end portion of said housing, a wall in and extending transversely of said housing, an electric motor disposed in said housing and carried by said wall, drive means for said cutter extending from said motor, reducing gears between said motor and said drive means, said drive means including a coupling portion and a hollow cylindrical portion, a recording drum carried by said hollow cylindrical portion, means to mount a strip of recording paper on said drum, a stylus carried by said housing and adapted to make a graph on the paper as the drum turns and moves axially with said hollow cylindrical portion, resilient means to exert uniform outward axial force on said hollow cylindrical member to urge said cutter against material being tested, means to resiliently counterbalance the cutter and parts which move therewith when the apparatus is used with its axis disposed vertically, said hollow cylindrical portion being provided with registering, longitudinally extending slots, a shaft connected to said drive means coaxial with and disposed in said hollow cylindrical portion, a pin extending transversely through Isaid shaft, a drive roller on each end portion of said pin and each disposed in one of the slots in said hollow cylindrical portion for transmitting rotary motion, while allowing relative axial motion, between said shaft and hollow cylindrical portion, a hollow cyindrical follower disposed in and movable with respect to said cutter, a rod extending rearwardly from said follower through the rear wall of -said cutter, and means resiliently biasing said follower outwardly with respect to said cutter, away from said shaft, and disposed inside of said hollow cylindrical portion.

13 14 11. An instrument as recited in claim 10, wherein the 2,620,654 12/ 1952 Campbell 73-78 front cover carries pointed members for engaging material under a test. OTHER REF ENCE 12. A11 instrument as recited in claim 10, including .an L. ER S electric circuit to the rnotor Iand switches mounted on 5 Amcle Tendemess of Meat Gets Accurate Test m the hand grips for controlling said circuit. Popular Science M011th1y- August 1930, Page 48- Referwes Cited by the Examiner RICHARD C. QUE1ssER,P/-immy Examiner.

UNITED STATES PATENTS J. W. MYRACLE, Assistant Examiner.

1,780,822 11/1930 Honda 7.3-104 10 

1. APPARATUS FOR DETERMINING THE TENDERNESS OF A MATERIAL COMPRISING A DULL CUTTER, MEANS SUCCESSIVELY PASSING THE CUTTER ALONG A PREDETERMINED PATH ON THE MATERIAL UNDER TEST TO CUT THE SAME, MEANS MAINTAINING A SUBSTANTIALLY CONSTANT FORCE BETWEEN THE CUTTER AND MATERIAL DURING EACH CUTTING PASS, AND MEANS FOR DETERMINING THE AVERAGE PENETRATION PER CUTTING PASS OF SAID CUTTER INTO SAID MATERIAL FOR A PLURALITY OF SUCH PASSES. 